I just brought home 4 days ago, mist in the morning
Unfortunately, your photo did not come through. I am unable to see the damage. Likely, misting once in the morning is not enough to sustain the humidity requirement for the plant. This is especially true if you use A/C in your home.
Here is an article that will help you with their care:
https://www.gardeningknowhow.com/ornamental/foliage/maidenhair-fern/maidenhair-fern-care.htm
The vine is dense, surrounding a palm tree, covering an area of around 25ft x 20ft and is up to 7ft high in places. It is right next to our conservatory and I'm worried about how far the roots have spread and what damage it could cause to our foundations and brickwork. Hedge trimmers won't cut it. Would a chainsaw work to cut such a dense vine? Assuming I can get it to ground level, what chemical treatment would kill the roots? I'm desperate to get it removed asap. Any advice would be gratefully received. Thank you.
I was given a heritage maiden hair fern from my sister-in-law in Panama City, Fla. It was given to her by my mother many years ago from Marianna, Fl. My grandmother from Thomasville, GA gave it to my Mother. I am thrilled to have it in my garden especially considering the age of the plant and the ancestral connection. I planted in in my garden in an area with filtered light. It slowly began dying so I moved it to a darker spot and have worked hard to keep the ground damp. It still looks poorly. Any advice?
It would be worth doing a soil test to see if your soil is too acidic. You may want to add some limestone if that's the case. Also, make sure you're not overwatering the plant. If you drown the roots, it will behave the same as a water-starved plant at first, but will die from root rot.
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/lower-acid-soil.htm
https://www.gardeningknowhow.com/ornamental/foliage/maidenhair-fern/maidenhair-fern-care.htm